Cardiovascular function and basics of physiology in microgravity

Aubert, André; Beckers, Frank; Verheyden, Bart

doi:10.2143/ac.60.2.2005024

Cited by 105 publications

(75 citation statements)

References 149 publications

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“…Changing gravity conditions have an important impact on almost all of the human body's systems, particularly the cardiovascular system (Pump et al 1999;Zhang 2001;Aubert et al 2005). Assuming the upright position for example, results in an autonomic reflex-response that consists of hemodynamic and cardiac rhythmic alterations to prevent blood from pooling in the legs and arterial blood pressure from falling (Cooke et al 1999).…”

Section: Introductionmentioning

confidence: 99%

Spectral characteristics of heart rate fluctuations during parabolic flight

Verheyden¹,

Beckers²,

Aubert³

2005

Eur J Appl Physiol

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Parabolic flight is used to create short successive periods of changing gravity in a range between 0 and 1.8 Gz (1 Gz: 9.81 m/s(2)). The purpose of the present study was to evaluate whether cyclic variations in heart rate during +/-20 s periods of stable gravity in parabolic flight reflect autonomic modulation of cardiac chronotropy. During the 29th and 32nd ESA parabolic flight campaign ECG and respiration were recorded in 13 healthy volunteers in both standing and supine postures. We developed and validated a spectral algorithm especially adapted to study frequency components of heart rate among ultrashort (+/-20 s) stable gravity periods of parabolic flight. A low frequency (LF) component, starting from the lowest measurable frequency (+/-0.05 Hz) up to 0.15 Hz was distinguished from a high frequency (HF) component, ranging from 0.16 Hz up to 0.4 Hz. Powers were calculated by integration between corresponding limits and represented in normalized units (nu). With our method, we were able to reproduce normal findings in the upright posture at 1 Gz, i.e., less power in the HF component compared to supine (HFnu: 0.18+/-0.09 vs. 0.40+/-0.16). These postural related differences are shown to be eliminated at 0 Gz (HFnu: 0.30+/-0.12 vs. 0.32+/-0.13) and amplified at 1.8 Gz phases (HFnu: 0.15+/-0.10 vs. 0.39+/-0.16) of parabolic flight. In the supine position no coherent differences were shown in the measured variables among different gravity phases. Our observations strongly indicate that spectral characteristics of heart rate fluctuations among stable gravity periods of parabolic flight reflect parasympathetic nervous system control of cardiac chronotropy. At 1 Gz, there is a normal upright situation with less parasympathetic modulation of heart rate compared to supine. This effect is augmented during 1.8 Gz-conditions due to a suppressed parasympathetic control of heart rate in the upright posture. Alternatively, at 0 Gz, increased parasympathetic control in standing position eliminates differences in cardiac chronotropy compared to supine.

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Section: Introductionmentioning

confidence: 99%

Spectral characteristics of heart rate fluctuations during parabolic flight

Verheyden¹,

Beckers²,

Aubert³

2005

Eur J Appl Physiol

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“…Such negative effects of microgravity have to be reversed when astronauts return to normal gravity especially following long-duration space flights [Aubert et al, 2005]. In particular, space flights affect the cardiovascular system by compromising cardiovascular performances, causing cardiac dysrhythmias, cardiac atrophy, orthostatic intolerance, and inducing a reduced aerobic capacity [Convertino, 2009].…”

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confidence: 99%

Modification of proteins secreted by endothelial cells during modeled low gravity exposure

Griffoni

Molfetta

Fantozzi

et al. 2011

J of Cellular Biochemistry

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The exposure of the human body to microgravity, conditions that occurs during space flights, causes significant changes in the cardiovascular system. Many cell types have been involved in these changes, and the endothelium seems to play a major role. In endothelial cells (EC), it has been shown that modeled low gravity impairs nitric oxide synthesis, cell adhesion, extracellular matrix composition, cytoskeleton organization, cytokines, and growth factors secretion. Nevertheless, detailed analysis of EC physiological changes induced by microgravity exposure is still lacking. Secretome analysis is one of the most promising approaches for the identification of biomarkers directly related to the physiopathological cellular state. In this study, we analyzed in details the modifications of EC secretome by using umbilical vein endothelial (HUVE) cells exposed to modeled low gravity conditions. By adopting a two-dimensional (2-D) proteomic approach, in conjunction with a technique for the compression of the dynamic range of proteins, we observed that modeled low gravity exposure of HUVE cells affected the secretion of proteins involved in the regulation of cytoskeleton assembly. Moreover, by using Luminex® suspension array systems, we found that the low gravity condition decreased in ECs the secretion of some key pro-inflammatory cytokines, including IL-1α and IL-8, and of the pro-angiogenic factor bFGF. On the contrary, microgravity increase the secretion of two chemokines (Rantes and Eotaxin), involved in leukocytes recruitment.

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“…The endothelium is supported by a basement membrane and surrounded by contractile cells of the smooth muscle cell family in arteries, veins, capillaries and lymphatics. These cells, which are responsible for the vascular tone and the control of permeability of the endothelium, participate in the disturbed distribution of the body fl uids during the initial exposure of humans to microgravity [7] and are probably involved in cardiovascular deconditioning affecting astronauts [8] . In venous hypertension and cardiac insuffi ciency on Earth, the oedema is gravity -dependent and located in the lower limbs.…”

Section: Similarity To Diseases On Earthmentioning

confidence: 99%

Biology of Adherent Cells in Microgravity

Lambert

Lapière

Nusgens

2007

Biology in Space and Life on Earth

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re , and Betty V. Nusgens Why Cell Biology Research in Microgravity?It is obvious that a journey in an orbiting spacecraft induces in most astronauts (cosmonauts) a signifi cant reduction of bone mass. This is accompanied by a large redistribution of the body fl uids and oedema of the upper part of the body and various disorders of the vascular system by alteration of the balance of the body fl uids. Altered renal function and bone resorption were suggested to be responsible for an increased propensity in forming kidney stones. The immune resistance has been considered as another side effect that is potentially responsible for various diseases, infectious and other, that could affect the crew of spacecrafts.Uni -and multicellular organisms are sensitive to environmental factors, chemical and physical, that modulate their vital functions. In space fl ights, the absence of the gravity stimulus under which all organisms have developed on Earth has been claimed to alter the precise equilibrium of physiological processes that is called health. Besides the lack of gravity, several additional disturbing elements need also to be considered, among which is increased cosmic radiations as a cause of cell damage by the induction of reactive oxygen species and mutations. Psychological stress, mainly in humans, is potentially responsible for endocrine disturbances that could also modify the operational activity of the cells. In all organisms, an exchange of information between cells modulates their functions. In multicellular organisms this situation is more complex since the different types of cells and their interactions, homo -and heterotypic, are in operation. This situation can be simplifi ed by dissociating the pluricellular organs and organisms: we can consider experimentally the participation of a single cell type and each extracellular message in the complex network of intracellular signalling that precisely controls the multiple pathways required for life. This analytical approach is most suitable for pinpointing the pieces of the puzzle that could be considered as a molecular target for pharmacological intervention. Both the pathology induced by Space exploration and its counterpart on Earth will equally benefi t from these investigations.The present chapter provides an overview of some specifi c facets of cell biological research in microgravity, their complexity and the need to continuously adapt 123 Biology in Space and Life on Earth. Effects of Spacefl ight on Biological Systems. Edited by Enno Brinckmann

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Cardiovascular function and basics of physiology in microgravity

Cited by 105 publications

References 149 publications

Spectral characteristics of heart rate fluctuations during parabolic flight

Spectral characteristics of heart rate fluctuations during parabolic flight

Modification of proteins secreted by endothelial cells during modeled low gravity exposure

Biology of Adherent Cells in Microgravity

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